Arduino starter kit, samt ett bygge på kopplingsdäck, temperatur och klocka.

/*
* temperature and clock sent to lcd display 16x2
* celsius with 2 decimals and time in format hh:mm:ss and day of week
*
* lcdtemperature.ino,
* code from Adafruit, page https://learn.adafruit.com/adafruit-arduino-lesson-12-lcd-dis...
*
* Adafruit Arduino - Lesson 12. Light and Temperature
*
* RTC clock code from http://tronixstuff.com/2014/12/01/tutorial-using-ds1307-and-d...
*
* Created: 8/5/2015 5:25:28 PM
* Author: Eos
*/

#include <LiquidCrystal.h>
#include "Wire.h"
#define DS3231_I2C_ADDRESS 0x68

int tempPin = 0;

// float highestTemp;
// float lowestTemp = 0.0;
//float highestLowestTemp;

// Convert normal decimal numbers to binary coded decimal
byte decToBcd(byte val)
{
return( (val/10*16) + (val%10) );
}

// Convert binary coded decimal to normal decimal numbers
byte bcdToDec(byte val)
{
return( (val/16*10) + (val%16) );
}

// BS E D4 D5 D6 D7
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);

void setup()
{
lcd.begin(16, 2);
// Serial.begin(9600);
Wire.begin();
// set the initial time here:
// DS3231 seconds, minutes, hours, day, date, month, year
// setDS3231time(00,44,21,6,14,8,15);
}

void setDS3231time(byte second, byte minute, byte hour, byte dayOfWeek, byte
dayOfMonth, byte month, byte year)
{
// sets time and date data to DS3231
Wire.beginTransmission(DS3231_I2C_ADDRESS);
Wire.write(0); // set next input to start at the seconds register
Wire.write(decToBcd(second)); // set seconds
Wire.write(decToBcd(minute)); // set minutes
Wire.write(decToBcd(hour)); // set hours
Wire.write(decToBcd(dayOfWeek)); // set day of week (1=Sunday, 7=Saturday)
Wire.write(decToBcd(dayOfMonth)); // set date (1 to 31)
Wire.write(decToBcd(month)); // set month
Wire.write(decToBcd(year)); // set year (0 to 99)
Wire.endTransmission();
}

void readDS3231time(byte *second,
byte *minute,
byte *hour,
byte *dayOfWeek,
byte *dayOfMonth,
byte *month,
byte *year)
{
Wire.beginTransmission(DS3231_I2C_ADDRESS);
Wire.write(0); // set DS3231 register pointer to 00h
Wire.endTransmission();
Wire.requestFrom(DS3231_I2C_ADDRESS, 7);
// request seven bytes of data from DS3231 starting from register 00h
*second = bcdToDec(Wire.read() & 0x7f);
*minute = bcdToDec(Wire.read());
*hour = bcdToDec(Wire.read() & 0x3f);
*dayOfWeek = bcdToDec(Wire.read());
*dayOfMonth = bcdToDec(Wire.read());
*month = bcdToDec(Wire.read());
*year = bcdToDec(Wire.read());
}

void displayTime()
{
byte second, minute, hour, dayOfWeek, dayOfMonth, month, year;
// retrieve data from DS3231
readDS3231time(&second, &minute, &hour, &dayOfWeek, &dayOfMonth, &month,
&year);
// send it to the lcd display 16x2
lcd.print(hour, DEC);
// convert the byte variable to a decimal number when displayed
lcd.print(":");
if (minute<10)
{
lcd.print("0");
}
lcd.print(minute, DEC);
lcd.print(":");
if (second<10)
{
lcd.print("0");
}
lcd.print(second, DEC);
/*
Serial.print(" ");
Serial.print(dayOfMonth, DEC);
Serial.print("/");
Serial.print(month, DEC);
Serial.print("/");
Serial.print(year, DEC);
Serial.print(" Day of week: ");
*/
switch(dayOfWeek){
case 1:
lcd.print(" Sunday");
break;
case 2:
lcd.print(" Monday");
break;
case 3:
lcd.print(" Tuesday");
break;
case 4:
lcd.print(" Wednday");
break;
case 5:
lcd.print(" Thurday");
break;
case 6:
lcd.print(" Friday");
break;
case 7:
lcd.print(" Saturday");
break;
}
}

void loop()
{
// Display Temperature in C
// Serial.println(lowestTemp);
int tempReading = analogRead(tempPin);
float tempVolts = (tempReading / 1024.0) * 5.0;
float tempC = (tempVolts - .5) * 100; // Celsius
float celsius = tempC;
//float tempF = tempC * 9.0 / 5.0 + 32.0; Fahrenheit

// Save highest and lowest temperature
/*highestLowestTemp = celsius;
if(lowestTemp < 1.0) {
lowestTemp = highestLowestTemp;
}
if(highestTemp < highestLowestTemp) {
highestTemp = highestLowestTemp;
}
if(lowestTemp > highestLowestTemp) {
lowestTemp = highestLowestTemp;
}
*/
// print to lcd 16x2
lcd.setCursor(0, 0);
lcd.print("T:");
lcd.setCursor(2, 0);
lcd.print(String(celsius, 2));
lcd.print(" Celsius");
lcd.setCursor(0, 1);
/*
lcd.print("H:");
lcd.setCursor(2, 1);
lcd.print(String(highestTemp, 2));
lcd.print(" L:");
lcd.print(String(lowestTemp, 2));
delay(500);
*/

displayTime(); // display the real-time clock data on the lcd display 16x2,
delay(1000); // every second
lcd.clear();
}